This invention relates generally to an improvement in a circular saw blade and, more specifically, to an improved cutter tip structure of the saw blade.
A circular saw generally includes a main body, a plurality of spaced apart gullets formed around the outer periphery of the main body, and a plurality of cutter tips secured to the periphery of the main body with each tip secured in juxtaposition to each gullet. There are two types of cutter teeth generally used for circular saw blades. One of them is of a type in which the cutter tips are set to form alternating left and right face bevels. The other is of a swage type in which the front or forward surface of each cutter tip is converged from the upper cutting edge toward its lower bottom portion.
FIG. 6 illustrates a plan view of one such swage type cutter tip designated generally as 10'. In the conventional swage type cutter tips 10', in which each cutting edge 11' is straight, the stress exerted against the cutting pressure P.sub.1 acts on the cutting edge 11' in the direction perpendicular to the cutting edge line. Since the cutter tip 10' is downwardly and backwardly converged in shape, the stress in both sides of the cutting edge 11' is failed to be fully supported by a body 3' to which the tip 10' is secured. Therefore, if the saw blade is overloaded by, for example, engaging a hard article, the cutter tips tend to be broken or damaged. Another problem associated with the conventional swage set type cutter tips as shown in FIG. 6 is related to the lowering of the cutting force of the blade, which is caused because the entire cutting edge is simultaneously brought into contact with an article to be cut. As a result, there are caused vibration of the blade, twisting of the cutting edge and the like troubles, resulting in the failure to produce a uniform and smooth cut surface.